fix(auth): correct endpoint path /auth/me → /auth/users/me

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

lib/core/auth/auth_datasource.dart

@@ -102,7 +102,7 @@ class AuthDatasource {
   /// Returns user profile if authenticated via the proxy.
   /// Throws 401 if not authenticated or accessing directly.
   Future<AuthSyncResponse> getCurrentUser() async {
-    final response = await _dio.get<Map<String, dynamic>>('/auth/me');
+    final response = await _dio.get<Map<String, dynamic>>('/auth/users/me');
     return AuthSyncResponse.fromJson(response.data!);
   }